Development of interspecific tomato hybrid derivative lines resistant to peanut bud necrosis virus

A field screening of F3 to F6 generation interspecific tomato hybrid-derived lines for Peanut Bud Necrosis Virus (PBNV) resistance was conducted at the Department of Horticulture, Agricultural College and Research Institute, Madurai, Tamil Nadu Agricultural University, Tamil Nadu, from 2019 to 2021. PBNV is one of the most devastating and economically significant viruses affecting tomatoes, leading to yield losses of up to 80-100 %. This study aimed to develop PBNV-resistant tomato lines suitable for commercial cultivation and assess the inheritance of resistance in advanced generations. Three tomato lines were crossed with ten wild species, generating 30 interspecific hybrids. Among these, four interspecific crosses viz., H4 (Arka Vikas × PSR 11668 - Solanum pimpinellifolium), H6 (Arka Vikas × EC 519809 - S. peruvianum), H17 (CO3 × EC 519791 - S. habrochaites) and H27 (PKM1 × EC 519791 - S. hirsutum) were screened in advanced generations under natural field conditions. No insecticide was applied throughout the entire crop production period. The disease incidence was evaluated on the 30th, 45th, 60th and 90th day after transplantation using the Percent Disease Incidence (PDI %) and disease reaction scale. Further in the F4 generation, a total of seventeen lines from the above four crosses were evaluated. In F5 and F6, generation 10 lines and 3 lines, respectively, from two crosses-viz., H6 (Arka Vikas × EC 519809, S. peruvianum) and H27 (PKM-1 × EC 519791) were evaluated. The results indicated that PBNV infection was present at all stages of crop growth. Among the four interspecific hybrids, the highest level of field resistance was observed in two lines of H6 (Arka Vikas × EC 519809 - S. peruvianum), followed by one line of H27 (PKM-1 × EC 519791). The resistant plants will either be released as a PBNV-resistant variety or utilized as a source of PBNV resistance in tomato breeding programs.